Israeli President Shimon Peres (left) shakes hands with Palestinian leader Mahmoud Abbas at a meeting with Pope Francis. The Mideast leaders planted an olive tree in the Vatican gardens as a peace gesture.

From left : Israeli President Shimon Peres, Palestinian President Mahmoud Abbas, Pope Francis and Orthodox Patriarch Bartholomew plant an olive tree saplings following a joint peace prayer on June 8, 2014 at the Vatican's garden's. The Vatican has defined the meeting between Israeli President Shimon Peres and Israeli President Shimon Peres as an "invocation for peace" but has stressed it will not be an "inter-religious prayer", which would have posed problems for the three faiths. In the Vatican Gardens, the prayers will be recited in chronological order of the world's three main monotheistic religions, starting with Judaism, followed by Christianity and then Islam. AFP PHOTO POOL / MAX ROSSIMax ROSSI/AFP/Getty Images

Pope Francis plunged head first into Mideast peacemaking Sunday, welcoming the Israeli and Palestinian presidents to the Vatican for a remarkable evening of peace prayers just weeks after the last round of U.S.-sponsored negotiations collapsed.

Israeli President Shimon Peres and Palestinian President Mahmoud Abbas joked and embraced in the foyer of the Vatican hotel where Francis lives and later in the Vatican gardens, where they joined Francis in presiding over a sunset invocation of Jewish, Christian and Muslim prayers.

Francis told the two men, who signed the Oslo peace accords in 1993, that he hoped the summit would mark "a new journey" toward peace. He said too many children had been killed by war and violence, and that their memory should instill the strength and patience to work for dialogue and coexistence.

"Peacemaking calls for courage, much more so than warfare," he said. "It calls for the courage to say yes to encounter and no to conflict."

Vatican officials have insisted that Francis had no political agenda in inviting the two leaders to pray at his home other than to rekindle a desire for peace. But the meeting could have greater symbolic significance, given that Francis was able to bring them together at all so soon after peace talks failed and at a time that the Israeli government is trying to isolate Abbas.

The meeting has also cemented Francis' reputation as a leader unhindered by diplomatic and theological protocol who is willing to go out on a limb for the sake of peace.

The unusual prayer summit was a feat of diplomatic and religious protocol, organized in the two weeks since Francis issued the surprise invitation to Peres and Abbas from Manger Square in Bethlehem.

At the conclusion, Francis, Peres and Abbas shook hands and planted an olive tree together in a sign of peace. Also on hand was the spiritual leader of the world's Orthodox Christians, to present a united Christian front.

Peres, 90, deviated from his prepared remarks in the garden to add a personal note as his term as Israeli president comes to an end.

"I was young. Now I am old," he said. "I experienced war. I tasted peace. Never will I forget the bereaved families - parents and children - who paid the cost of war. And all my life I shall never stop to act for peace, for generations to come.